/Engine/Source/Runtime/NetworkFile/Public/NetworkPlatformFile.h
Sends a message to the file server, and will block until it's complete. Will return immediately if the file manager doesn't support talking to a server.
true if the message was sent to server and it returned success, or false if there is no server, or the command failed
virtual bool SendMessageToServer ( const TCHAR * Message, [IPlatformFile::IFileServerMessageHandler](API\Runtime\Core\GenericPlatform\IPlatformFile\IFileServerMessageHandler) * Handler )